GL Balance Report output not Matching with Material Stock

Hi,

Can we Match Reports MB5B (Stock on Posting Date) and S_ALR_87012301 (G/L Account Balance)???

Till March these reports are matching but from April 11, data not matching..

In tcode MB5B, we are looking Valuated Stock of Materials and in tcode s_alr_87012301 showing balances, which were matching earlier..

Plz guide...